The Senate appeared to be on track Tuesday to clear a House-passed small-business capital formation bill this week, but the rare spectacle of bipartisanship and inter-chamber cooperation might be short-lived. There is no grand push for other bills, and other more contentious issues, such as the budget, are beginning to crowd the legislative calendar.

Aside from the capital formation bill, other possibilities include a bill that would strengthen the law against Members of Congress engaging in insider trading and a proposal by House Republicans that would give a 20 percent tax cut to small businesses.

“There are plenty of opportunities for bipartisanship in the coming weeks,” a Senate Democratic leadership aide said.

A House GOP aide agreed that bipartisanship is possible but stressed that both parties must be open to seizing the opportunities. But such circumstances will likely become more difficult to achieve as the November elections grow nearer, the aides acknowledged.

The aides’ comments came as the Senate was poised to pass the capital formation bill — formally known as the Jumpstart Our Business Startups Act — which was approved by the House, 390-23, earlier this month. The legislation, a priority for House Majority Leader Eric Cantor (R-Va.), was embraced by President Barack Obama, which gave the measure momentum in a Congress otherwise defined by partisan bickering.

The Senate is expected to clear the measure before the end of the week. On Tuesday, the Senate rejected a Democratic amendment, 55-44, that would have attached increased consumer protection provisions to the bill. Sixty votes were needed for the measure to continue through the legislative process.

The Senate also defeated a Democratic amendment, 55-44, that would have reauthorized the Export-Import Bank after Senate Minority Leader Mitch McConnell (R-Ky.) urged his Members to oppose the proposal.

McConnell said that while there is support from Republicans for the bank, which helps finance exports to foreign buyers, he wants to ensure the underlying bill gets to the president as soon as possible. Conservatives, including Sen. Jim DeMint (R-S.C.), came out against the Export-Import Bank proposal, calling it corporate welfare.

“It’s important that we get this down to the president,” McConnell said, adding that attaching the bank provision would delay the bill’s enactment.

Senate Majority Leader Harry Reid (D-Nev.) argued that the measure should be attached to the House bill because it would create jobs and needs to be reauthorized as soon as possible. Reid and other Democratic leaders appeared to be caught off guard when the amendment did not pass and held a caucus meeting after the vote.

Reid’s willingness to move to the House-passed insider trading bill — also known as the Stop Trading on Congressional Knowledge Act — comes after he failed to get consent to go to conference with the House. The Senate passed its own version in February.

Reid said he would look to take up the House-passed bill rather than take the time needed to wade through procedural hurdles to conference with the House.

The measure was designed to reinforce a ban on Congressional insider trading. But during Senate debate on the measure earlier this year, it grew to encompass a politically uncomfortable discussion on Congressional ethics.

The Senate added numerous provisions in an amendment vote-a-rama. Sen. Bob Corker (R-Tenn.) called it an exercise in “self-flagellation,” and Sen. John McCain (R-Ariz.) described it as a “feeding frenzy.”

House GOP leaders subsequently removed two key Senate provisions before sending the legislation to the floor, where it passed on the suspension calendar, 417-2, last month.

The first key provision removed was sponsored by Senate Judiciary ranking member Chuck Grassley (R-Iowa) and would have required political intelligence consultants to register as lobbyists. The second, from Senate Judiciary Chairman Patrick Leahy (D-Vt.) and Sen. John Cornyn (R-Texas), broadened anti-corruption law.

Reid’s positioning comes after Grassley and Leahy wrote to Reid and McConnell on Monday urging them to go to conference, which would give them an opportunity to get their provisions back in the bill.

“The Senate passed both of these amendments with strong, bipartisan support. Unfortunately, the House stripped both provisions from the STOCK Act without a vote. The Senate should act to ensure that the key improvements it made to this bill are incorporated into the final legislation that Congress passes,” the letter said.

Regarding the House GOP bill to give small businesses a 20 percent tax cut, a Senate Democratic aide said that most Democrats, and the president, support the idea but have problems with the House proposal because it is likely too broad.

The aide said that all businesses with fewer than 500 employees are expected to be eligible for the tax cut and that includes some pretty big companies, such as sport franchises and hedge funds.

“It should be more targeted,” the aide said. “Hedge funds don’t need help.”